<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
    <input type="text" v-model="num1">
    <input type="text" v-model="num2">
    <input type="button" value="加" @click="f(1)">
    <input type="button" value="减" @click="f(2)">
    <input type="button" value="乘" @click="f(3)">
    <input type="button" value="除" @click="f(4)">
    <div>结果:{{result}}</div>
</div>
<script src="js/vue.min.js"></script>
<script>
    let v = new Vue({
        el:"body>div",
        data:{
            num1:"",num2:"",result:""
        },
        methods:{
          f(x){
             if (isNaN(v.num1)||isNaN(v.num2)){
                 v.result="输入错误!";
                 return;
             }
             switch (x){
                 case 1:
                     v.result=v.num1*1+v.num2*1;
                     break;
                 case 2:
                     v.result=v.num1-v.num2;
                     break;
                 case 3:
                     v.result=v.num1*v.num2;
                     break;
                 case 4:
                     v.result=v.num1/v.num2;
                     break;
             }
          }
        }
    })
</script>
</body>
</html>